Uploaded Video File Does Not Show in Library

Hi, I just added videopress support to my blog today. I uploaded an MP4 file, which is showing as 864 MB on my computer (i.e., below the 1 GB upload limit). At the end of the upload, I received an error message, and the file does not show in the library now, but the space counter on top of the library page indicates I have used those 864 MB now. I now have 2 issues: 1) How do I upload that file - since it is less than 1 GB, it should upload, so not sure why I'm getting the error message; 2) How can I clean up my used space - I don't want to be "penalized" with 864 MB for space that I cannot use since the file is not showing up.